Process of producing ammonia and aluminium compounds.



STATES PATENT OFFICE.

Ii'lf 13.35133 ALVJIN MITTASCH, 01: LUD'WIGSHAFEN-ON-THE RHINE, GERMANY,

Ti? .BJLUISCHE ANILIN 8r, SGDA FABRIK, O'F LUDWIGSHAFEN-ON-THE.E-Hfili'li, GERMANY, A CGRPORATIOII- OF BADEN.

PBEOEESS 9F ZRODUCIN G AMMONIA AND ALUMINIUM GOMPOUNDS.

w v W? More, m8.

Tito Brawing.

" all whom it may concern:

lie it known that we, CARL Boson, Ph. D., and ii LWlN hi'i'r'r sci-i, Pl1)., chemists, subjects, respectively, of the King of Prussia and theKing of Saxony, residingat Ludvigshafen on-tiie-Rliiiie, Germany, havein- "vent-ed new and useful Improvements in the Process oi ProducingAmmonia and Aluminium Compounds, of which the following is aspecification.

it is known that aluminium nitrid, upon being treated with Water or withalkali or with acid, can he decomposed giving rise to ammonia, buthitherto no process has been described by which ammonia and pure aluiuiucompounds can be obtained from raw or impure mixtures containingalumini-' um nitridsuch as can be obtained by heat ing mineralscontaining aluminium With carbon in a currentof n.itrogengas, theimpurities present being chiefly nitride, car bids, and oxide of siliconand titanium. We have found that We can obtain ammonia (under which termwe include both free ammonia and also ammonia in the form of its salts)and practically pure aluminium com poiuuls from such raw or impuremixtures containing aluminium nitrid by treating the said mixtures withacid, or with alkali, if care be taken that either limited uantities oi!the acid, or alkali, are employs i, or that "2 reaction, is carried outunder mild condiu-a. that is to say, by suitably choosing theconcentration of the ingredients, the temperature. and the time duringwhich the re A We prefer to carry out :Hilfltl takes place. the reactionaccording to our invention by restricting; the quantity of acid, oralkaline, reagent used rather than by loweringthe concentration thereof,or diminishing the temperature at which, or the time during winch, thereaction is carried out.

it a mineral. acid or an organic acid be allowed to act upon the mixturecontaininnaluu'iinium nitrid according to the prom or our invention, thequantity thereof can be chosen so that either the nitrogen of theahuuinium nitrid is converted into the ammonium salt and. also thealuminium is converted into the aluminium salt oi the acid employed, ora smaller amount of acid 7 Specification of Letters Patent. PatentedNov, 12, i912, Application filed July 7, 1910. Serial No. ?0,863. I

can be employed so that only the nitrogen of the aluminium nitrid isconverted into the ammonium salt and goes into solution. In this lattercase the reaction which takes place can be represented bythe, equation;

-where It represents a suitable acid rudihiil.

aluminium nitrid mixture to the action of an aluminium salt so placecorresponding, equat1on:--

Other salts, such for instance as iron I of which the bases areprecipitated by ammonia, act in a similar manner and instead of suchsalts, acid salts, such for in-,

that a process takes for T instance, to, the

chlorid,

stance as bisulfates, can 'be employed in car-' rying out the process ofour invention. The whole of the acid can be added to the aluminiumnitrid at once, or it can be added gradually, and the water necessarycan, if desired, be employed in theform of steam.

if desired, the mixture containing the nitrid can he treated with water,or steam, before the treatment with the acid takes place, and further anacid, such as carbon dioxid, may be employed which is incapable offorming stable salts with aluminium.

When acting with an alkaline reagent according to our invention onmixtunescontaining aluminium nitrid, it is adv'atageous to use from one,t-o't-wo, molecular proportions oi alkali hydroxid for each molecularproportion of aluminium nitrid contained in the raw, or impure, product.In this way saturated aluminat-e lyes canbe produced urc alufrom whichit is easy to. prepare uality minium hydrate. The quantity M resent,-the. 65

' an-alka-li, and in this way be separated from I jto our inventioneither by means of acidor alkali,

neutral. salt by which especially in the case twenty-two pcr but thealuminium generally be filtered away and any undissolved aluminiumcompound 'alsof'be used for p :nnnrumdouble salts, in which case it isonly "necessary to add a f 'where' small quantities of alkali areemcreased. This method of procedure is particularly advantageous when,it is invention. r I, The following examples trate further ing eighteenper the aluminium.

worked'up in any desired manner.

with coldd'lute sulfuric acid and Example and ten parts of forty-eightpercent. sulfuric acid and'one hundredparts of raw is obtainedcontainand ammonium sulshort time a solid mass ing aluminium hydratefate. The ammonium sul'tate can be extracted by means of watelr and thealuminium hydrate remains behind and can be ronverted into a salt bytreatment with the eorresponding acid.

Example 3: Heat together in an autoclave, while stirring, at atemperature of from one hundred and twenty, to onehundred and forty.degrees eenti grade, two'hun' dred and fifty parts of twenty per cent.ac'ctie acid and titty parts of crude aluminium nitrid containingtwenty-four per eent. of combined nitrogen, After a few hours filter oilandwash the residue. The solution contains ammonium, acetate which canbe separated by evaporation.

Example 4: Heat sixty parts of aluminium nitrid containing thirty percent. of ni trogen combined with aluminium and two per cent. combinedwith silicon (the aluminimu nitrid should prcterably have been purifiedby treating it with air at a red heat) and two hundred and forty partsof water at from ninety, to one hundred, degrees .centigrade in a vesselpim ided with astirring apparatus and with a reflux condenser. At thesame time pass nitric acid gas into the vessel in such a manner that thesolution continually remains practically neutral. As soon as thetheoretical amount of nitric acid hasbeen used, or as soon asa testshows that all the aluminium nitrid has been split up, subject the massto filtration, whereby a concentrated solution of ammonium nitrate isobtained, while the aluminium hydroxid contained in can be obtainedtherefrom by means 0 requisite quantity of acid or alkali. Example 5:Heat together, in an autoclave, for one bout at one hundred and tendegrees eentigrade, eightyparts of aluminium-silicon-titanium nitrid(containing sixof the alkaline reagent (which may include an oXid, orhydroXid, or a suitable salt) can, however. be chosen, if desired, sothat the l aluminium nitrid compound is decomposed, l

hydroxid produced is not, or is'not completely, brought into solution.'The basic compound can be added all i at once before the reaction takesplace, or it t can be'added gradually during the reactioin If desired,the nitrid can be treated with water or steam and subsequently with thedefinite quantity of alkali. The aluminate solutionv produced during thereaction can can be brought intosolution either by means of an acid, or

the original impurities contained mixed thealuminium nitrid. The rawproduct obtained according toour invention can the production ofalusuitable acid or acid salt, and any alkalrwhich may b required. Whencarrying out. the process according it is often advantageous to add aployed" the evolution of ammonia is indesired to prepare aluminiumdouble salts, in which case of course the salt chosenis that of an acidin accordance with the double salt reuired. V

If desired, the mixture containing aluminium nitrid can be purified inany suitable manner before it isreacted upon with acid or alkaliaccording-to the process of this the will serve to illusof ourinvention, is not confined to these exthe nature which, however,

amples, The parts are by weight. I teen )er cent. of nitrogen combinedwith the p Example 1: Het together, for -a few 'ahnmniuml prepared byheating bauxite, hours, at about on hundred degrees centiwhich containstitanium and silicon, with parts of a cent. sulfuric acid and fifty msof" silicon-aluminium nitrid containcent. of nitrogen atta to thesilicon and eight per cent. attachedto Upon filtration, a solutioncontaining ammonium sulfate and aluminijinnv sulfate is obtained andthis can be esired, the silicon alumininm mtrid can be purified beforebeing used,- by treating. it

' "filtering it.

2: Digest together two hundre grade, three hundred and sixty carbon inthe presence of nitrogen gas, an

three hundred and sixty parts of eighteen the ammoniato escape, filteroff the solution of aluminate and work it up into aluminium hydrate.

Example (3: Heat together, in an autoclave, for-three hours, at from onehundred and twenty, to one hundred and thirty, dcgrccs centigrade, onehundred parts of raw aluminium nitrid containing twenty-eight per cent.of combined nitrogen and considerable quantities of iron, coal, andsilicon compounds, one hundred and twenty parts of caustic soda and sixhundred parts of water. The ammonia can be allowed to esape periodicallyor continuously. Toward be close at the operation, place the vesselaluminium 'nitrid which is mixed with siliconeotnpounds and containstwenty-eight per cent. of combined" nitrogen. -After a the residue percent. caustic soda solution. Then allow minium hydroxid is obtained.

under reduced pressure so that. the last portions of ammonia areremoved, then filter and treat the filtrate with a small quantity ofcrystallized aluminium hydrate, and then shake, or stir, whereupon avery pure alu- In this example, if desired, the reaction can be carriedout at a temperature of one hundred degrees centigrade, or' less, andthe last portions of ammonia can be driven out by passing a current oiindifferent gas through. the solution.

Example 7: Boil together twenty-two parts of potassiun'i carbonate,three hundred and fifty parts of water and fifty parts of a mixturecontaining seventy-six per cent. of alun'iinium nitrid and nine percent. of silicon nitrid. When the first evolution of ammonia begins todecrease, add gradually nine parts of caustic potash and heat until allthe aluminium nitrid is decomposed and pass a. current of air throughthe solution in order to drive oil any dissolved ammonia. The solutioncontains potassium aluminate and any free aluminium hydroxid can befiltered oil and used in any suitable manner. If desired, however, theWhole reaction mixture can-be treated with three hundred and fifty partsof forty-eight per cent. sulfuric acid and forty-two parts of potassiumsulfate and the hot solution can he filtered, whereupon, on cooling,potash alum is obtained in crystals.

Example 8: Heat together, for two hours, in an autoclave, at onehundredand forty degrees centigrade, ten parts of aluminium nitrid mixedwith silicates, silicon carbid and unaltered alumina, and containingtwenty-seven per cent. of combined nitrogen, with nine parts ofquicklime, and fifty parts of'water, and then drive oil the our moniafrom the reaction mass. Alkali aluminate can. he obtained by treatmentwith soda, or, if the required quantity of sult'urie acid be added,aluminium sulfate can he obtained.

Example 9: Mix aluminiumtitanium nitrid with the quantity of causticsoda necessary for the formation of sodium aluminate and heat the massin a tube for four hours at from one hundred and titty, to two hundred,degrees centigrade, while passing steam through the-tube. Sodiumalulninate can be separated from the undecomposed titanium nitrid byextracting it with Water.

Example 10: Boil together one hundred parts of crude aluminium nitrid,containing silicon nitrid, and four hundred and thirty parts of anaqueous solution containing two parts of caustic soda and forty parts ofcommon salt. The nitrogen of the aluminium nitrid is very rapidlyerolved in the form of ammonia.

Now What We claim is 1. The process of producing ammonia.

and aluminium;compounds from crude mixtitresconta'iningjaluitfi'niurn,nitrid by heating such mixtures with at,'ecomposing agent under such mild conditions that the aluminium nitridis converted into an ammoniacal product and an alumina product, but sothat the other ingredients of the practically unaltered.

2. The process of producing ammonia and aluminium compounds from crudemixtures containing aluminium nitrid-by heating such mixtures with suchan amount of a compound with an alkaline reaction that thenitrogen isconverted into ammonia and the aluminium into an aluminium compoundcontaining oxygen but. so that the other ingredients of the mixtureremain practically unaltered.

3. The process of producing ammonia and aluminium compounds from crudemixtures containing aluminium nitrid by heating such mixtures with suchan amount of a compound with an alkaline reaction that the nitrogen isconverted intoammonia and the aluminium into aluminate but so that theother ingredients of the mixture remain practically unaltered.

43 The aluminium compounds from crude mixtures containing aluminiumnitrid by heating such mixtures with such an amount of caustic soda thatthe nitrogen is converted into ammonia and the aluminium into analuminium compound containing oxygen but so that the other ingredientsof the mixture remain practically unaltered.

5. The process of producing ammonia and aluminium compounds from crudemixtures containing aluminium nitrid by heating such mixtures withv suchan amount of caustic soda that the nitrogen is convert-ed into ammoniaand the aluminium int'd. sodium aluminate but so that the otheringredients of the mixture remain practically unaltered.

The process of producing ammonia and aluminium compounds from crudemixtures containing aluminium nitrid by heating such mixtures with fromone to two molecular proportions of caustic soda for each molec ularproportion of aluminium nitrid but so that the other ingredients of themixture remain practically unaltered.

7. The process of producing ammonia and aluminium compounds from crudemixtures containing aluminium nitrid by heating such mixtures with fromone to two molecular proportions of caustic soda, for each molecularproportion ofaluminmin nitrid awhile so thatthe' other.

employing pressure but ingredients of the I mixture remain practicallyunaltered.

mixture retiiain,

process of producing ammonia and 8. The process of producing ammonia and1 aluminium compounds from crude mixtures containing aluminium; nitridby heating such mixtures with from one to'two molecular proportions ofoausiic soda for each molecouts of the mixture remain practically unsetour hands in the presence of two subuiur proportion of aluminium nitrid,while scribing witnesses. employing a pressure of from one to five CARLBOSCH. atmospheres but so that the other ingredi ALWIN MI'TFKSCf-E.

\ Witnesses: I J. Amie. LLOYD,

altered. I

' In testimony whereof we have hereunto ERNEST L. IVES.

